This book covers information on the economics; botany, taxonomy, and origin; germplasm resources; cytogenetics and nuclear DNA; genetic improvement efforts of scion cultivars; genetic and genomic improvement efforts of rootstocks; genetic and physical mapping; genomic resources; genome and epigenome; regulatory sequences; utility of whole-genome sequencing and gene editing in trait dissection; flowering and juvenility; cold hardiness and dormancy; fruit color development; fruit acidity and sugar content; metabolomics; biology and genomics of the microbiome; apple domestication; as well as other 'omics' opportunities and challenges for genetic improvement of the apple.

The cultivated apple (Malus x domestica Borkh.) is one of the most important tree fruit crops of temperate regions of the world. It is widely cultivated and grown in North America, Europe, and Asia. The apple fruit is a highly desirable fruit due to its flavor, sugar and acid content, metabolites, aroma, as well as its overall texture and palatability. Furthermore, it is a rich source of important nutrients, including antioxidants, vitamins, and dietary fiber.